Aqueous-dispersing composition of crosslinkable fluorine-containing resin

ABSTRACT

An aqueous-dispersing composition of a crosslinkable fluorine-containing resin which comprises an aqueous dispersion of a fluorine-containing seed polymer (B) obtained by seed-polymerizing a non-fluorine-containing monomer containing a non-fluorine-containing monomer (a) having carboxyl group and/or acetoacetyl group and a reactive α,β-unsaturated group, in an aqueous medium in the presence of particles of a fluorine-containing polymer (A) and a polyvalent metal compound capable of metal crosslinking.

FIELD OF THE INVENTION

The present invention relates to an aqueous-dispersing composition of acrosslinkable fluorine-containing resin for an aqueous coating or paintfor use in the interior and exterior of a building.

DESCRIPTION OF THE RELATED ART

In the field of paints, various aqueous dispersions have been hithertoproposed. JP-A-5-32841, JP-B-47-15597 and JP-B-49-1458 disclosecompositions comprising, as essential components, a synthetic resincrosslinkable with metal and a polyvalent metal compound. However, whenthese compositions are used in applications for the interior andexterior of a building, since a coating film thereof is easilydeteriorated by an aqueous alkali medium, there is a disadvantage inthat it is difficult to apply such compositions particularly to alkalisubstrates of concrete, ALC and slate.

In view of the above, an object of the present invention is to providean aqueous dispersing composition of a fluorine-containing resincrosslinkable at room temperature, which is useful as a binder forcoating and excellent in film forming property, stain-proofing property,weather resistance, chemical resistance and storage stability, bycombining a specific fluorine-containing polymer with a polyvalent metalcompound which can form a metal crosslinking structure.

SUMMARY OF THE INVENTION

The present invention relates to an aqueous-dispersing composition ofcrosslinkable fluorine-containing resin, which comprises ametal-crosslinking-formable polyvalent metal compound and an aqueousdispersion of fluorine-containing seed polymer (B) obtained byseed-polymerizing a non-fluorine-containing monomer containing anon-fluorine-containing monomer (a) having a carboxyl group and/oracetoacetyl group and a reactive α,β-unsaturated group, in an aqueousmedium in the presence of particles of a fluorine-containing polymer(A).

DETAILED DESCRIPTION OF THE INVENTION

The aqueous-dispersing composition of resin of the present inventioncomprises a metal-crosslinking-formable polyvalent metal compound and anaqueous dispersion of a fluorine-containing seed polymer (B) obtained byseed-polymerizing a non-fluorine-containing monomer containing anon-fluorine-containing monomer (a) having a specific functional groupin an aqueous medium in the presence of particles of afluorine-containing polymer (A). Each component is explained below.

1. Aqueous dispersion of Particles of Fluorine-containing Copolymer (A)

Examples of the fluorine-containing polymer (A) are polymers obtained bypolymerizing a fluoroolefin as an essential component.

Examples of the fluoroolefin are, for instance, fluoroolefins havingabout 2 to 4 carbon atoms such as vinyl fluoride, vinylidene fluoride(VdF), tetrafluoroethylene (TFE), chlorotrifluoroethylene (CTFE),hexafluoropropylene (HEP) and trifluoroethylene.

Examples of the fluoroolefin polymer are homopolymers of thosefluoroolefins or known copolymers comprising two or more of thosefluoroolefins. Examples thereof are homopolymers of VdF, TFE and CTFE,VdF/TFE copolymer, VdF/HFP copolymer, VdF/CTFE copolymer, VdF/TFE/CTFEcopolymer, VdF/TFE/HFP copolymer, TFE/HFP copolymer, and the like.

An aqueous dispersion of particles of the fluoroolefin polymers can beprepared through usual emulsion polymerization, namely, byemulsion-polymerizing a fluoroolefin monomer or monomer mixture in thepresence of an emulsifying agent in an amount of not more than 5% byweight, preferably not more than 1% by weight on the basis of water.

Water used for the emulsion polymerization is preferably de-ionizedwater. Also it is preferable that the emulsifying agent is afluorine-containing surfactant. Further, a reactive fluorine-containingemulsifying agent can be used. It is also possible to use a slightamount of a non-fluorine-containing nonionic emulsifying agent incombination.

The fluorine-containing emulsifying agent is one or a mixture ofcompounds having a structure containing fluorine atoms and havingsurface activity. Examples thereof are an acid represented byX(CF₂)_(n)COOH, in which n is an integer of 6 to 20, X is F or H, itsmetal salt, ammonium salt, amine salt or quaternary ammonium salt; anacid represented by Y(CH₂CF₂)_(m)COOH, in which m is an integer of 6 to13, Y is F or Cl, its metal salt, ammonium salt, amine salt orquaternary ammonium salt; and the like. In addition, it is possible touse solely a reactive emulsifying agent disclosed in JP-A-8-67795 and touse the reactive emulsifying agent in combination with theabove-mentioned fluorine-containing emulsifying agent. Also it ispossible to use a non-fluorine-containing nonionic emulsifying agentdisclosed in JP-A-7-90153 together.

Examples of the other fluoroolefin polymer are, for instance, copolymerswith a non-fluorine-containing monomer (excluding the above-mentionednon-fluorine-containing monomer (a) having functional group) beingcopolymerizable with fluoroolefin.

Examples of the non-fluorine-containing monomer copolymerizable withfluoroolefin are, for instance, α-olefins such as ethylene, propyleneand isobutylene; vinyl ethers such as ethyl vinyl ether (EVE),cyclohexyl vinyl ether (CHVE), hydroxybutyl vinyl ether (HBVE), butylvinyl ether, isobutyl vinyl ether, methyl vinyl ether andpolyoxyethylene vinyl ether; alkenyls such as polyoxyethylene allylether, ethyl allyl ether, hydroxyethyl allyl ether, allyl alcohol andally ether; vinyl esters such as vinyl acetate, vinyl lactate, vinylbutyrate, vinyl pivalate, vinyl benzoate, and VEOVA9 and VEOVA10 (namesof products available from Shell Chemical Co., Ltd.); and the like.Particularly α-olefins, vinyl ethers, vinyl esters and alkenyls arepreferably used.

Examples of the copolymers are TFE/propylene copolymer, TFE/ethylenecopolymer, TFE/vinyl ester copolymers, TFE/vinyl ether copolymers,HFP/vinyl ether copolymers, HFP/vinyl ester copolymers, CTFE/vinyl ethercopolymers, and the like. Further, there are copolymers comprising threeor more monomers, i.e. copolymers containing the above-mentionedcopolymer and as a modifying monomer, the above-mentioned monomercopolymerizable with fluoroolefin in an amount of not more than 30% bymole.

The aqueous dispersions of particles of the fluoroolefin copolymers canbe prepared through usual emulsion polymerization. The emulsionpolymerization method may be the same as in the polymerization method ofthe fluoroolefin polymer of above (1) except that the mixture of thefluoroolefin and monomer copolymerizable with fluoroolefin is used.

It is preferable that the fluoroolefin monomer is contained in thecopolymers comprising the fluoroolefin and non-fluorine-containingmonomer in an amount of 20 to 80% by mole. When an amount of thefluoroolefin monomer is less than 20% by mole, sufficient weatherresistance cannot be exhibited. When the amount is more than 80% bymole, there is a tendency that at the time of making a coating andforming a coating film, a lowering of appearance occurs.

The aqueous dispersion of fluorine-containing seed polymer (B) of thepresent invention can be prepared by seed-polymerizing anon-fluorine-containing monomer (a) having carboxyl group and/oracetoacetyl group and a reactive α,β-unsaturated group in an aqueousmedium in the presence of particles of the above-mentionedfluorine-containing polymer (A).

The non-fluorine-containing α,β-unsaturated monomer (a) having acarboxyl group and/or acetoacetyl group functions to impartstain-proofing property and stain removable property to a coating filmby coordinate-bonding to a metal compound and forming a crosslinkedstructure.

Examples of the non-fluorine-containing α,β-unsaturated monomer havingcarboxyl group are, for instance, α,β-unsaturated carboxylic acids suchas acrylic acid, methacrylic acid, itaconic acid, succinic acid,succinic anhydride, fumaric acid, fumaric anhydride, crotonic acid,maleic acid and maleic anhydride. Among them, acrylic acid andmethacrylic acid are preferred from the viewpoint of copolymerizability.

A preferred non-fluorine-containing α,β-unsaturated monomer havingacetoacetyl group is, for example, acetoacetoxyethyl methacrylate(AAEM).

As the monomer (a), one or a mixture of two or more monomers is used.

It is preferable that the non-fluorine-containing monomer for the seedpolymerization contains a non-fluorine-containing monomer other than themonomer (a).

Examples of such a non-fluorine-containing monomer are reactiveα,β-unsaturated monomers such as alkyl acrylate having an alkyl of Cl toC18 and alkyl methacrylate having an alkyl of Cl to C18 and monomershaving an ethylenically unsaturated unit copolymerizable therewith.

As the alkyl acrylates having an alkyl of Cl to C18, there are, forexample, methyl acrylate, ethyl acrylate, propyl acrylate, n-butylacrylate, isobutyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate andthe like.

As the alkyl methacrylates having an alkyl of Cl to C18, there are, forexample, methyl methacrylate, ethyl methacrylate, propyl methacrylate,n-propyl methacrylate, isobutyl methacrylate, cyclohexyl methacrylate,lauryl methacrylate and the like.

For the purposes of enhancing solvent resistance and water resistance,it is possible to copolymerize a polyfunctional monomer such as ethyleneglycol dimethacrylate or propylene glycol dimethacrylate.

Examples of the monomer which has an ethylenically unsaturated unitcopolymerizable with the acrylate and/or the methacrylate are, forinstance, a-olefins such as ethylene, propylene and isobutylene; vinylethers such as ethyl vinyl ether (EVE), cyclohexyl vinyl ether (CHVE),hydroxybutyl vinyl ether (HBVE), butyl vinyl ether, isobutyl vinylether, methyl vinyl ether and polyoxyethylene vinyl ether; alkenyls suchas polyoxyethylene allyl ether, ethyl allyl ether, hydroxyethyl allylether, allyl alcohol and allyl ether; vinyl esters such as vinylacetate, vinyl lactate, vinyl butylate, vinyl pivalate, vinyl benzoate,and VEOVA9 and VEOVA10 (names of products available from Shell ChemicalCo., Ltd.); aromatic vinyl compounds such as styrene, cx-methyl styreneand p-tert-butyl styrene; acrylonitrile; and the like.

It is preferable that the monomer (a) is contained in the obtainedfluorine-containing seed polymer (B) in an amount of from 0.1 to 10% byweight, particularly from 0.5 to 5% by weight. When the content of themonomer (a) is decreased, an effect of improvement in stain-proofingproperty and stain removable property tends to be lowered, and when thecontent is increased, coating stability is lowered and the appearance ofthe coating film is lowered.

In the present invention, it is preferable that the seed polymer (B)contains the fluoroolefin monomer in an amount of 20 to 90% by mole onthe basis of the whole seed polymer. When the amount of fluoroolefinmonomer is less than 20% by mole, weather resistance is not exhibitedsufficiently, and when the amount is more than 90% by mole, at the timeof making a coating and forming a coating film, appearance of the filmis lowered.

The seed polymerization of the non-fluorine-containing monomercontaining the monomer (a) can be carried out under the same conditionsas in usual emulsion polymerization. For example, to a water mediumcontaining particles of the fluorine-containing polymer (A), asurfactant, a polymerization initiator and a chain transfer agent areadded, and as the case demands, a chelating agent, a pH control agent, asolvent, etc., are also added. Then the reaction is conducted at about20° C. to about 90° C. for about 0.5 hour to about 6 hours.

When the emulsion polymerization of the non-fluorine-containing monomeris carried out in the presence of particles of the fluorine-containingpolymer, it seems that at first, there occurs swelling of the particlesof the fluorine-containing polymer with the monomer. At that time, themixture achieves a state of an aqueous dispersion of the particles offluorine-containing polymer dissolved uniformly in the monomer. Then,the non-fluorine-containing monomer is polymerized by adding aninitiator, thus forming single phase polymer blend particles, in whichthe molecular chains of the polymers are entangled with each other.

As a surfactant, an anionic surfactant, nonionic surfactant or acombination of the anionic and nonionic surfactants is used, and as thecase demands, an amphoteric surfactant can be used.

Examples of the anionic surfactant are a sulfate of higher alcohol,sodium alkylsulfonate, sodium alkylbenzenesulfonate, sodiumdialkylsulfosuccinate, sodium alkyldiphenylether disulfonate, and thelike. Examples of the nonionic surfactant are polyoxyethylene alkylethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkylesters, polyoxyethylene alkyl phenyl esters, sorbitan alkyl esters,glycerol esters, their derivatives, and the like.

The amphoteric surfactant includes lauryl betaine, and the like.Further, a so-called reactive emulsifying agent which is copolymerizablewith the ethylenically unsaturated monomer can be used.

Examples of the commercially available reactive emulsifying agent areBlemmar PE-350, Blemmar PME-400 and Blemmar 7OPEP35OB (available fromNOF Corporation); NK Ester M40G, NK Ester M-90G and NK Ester M-230G(available from Shin-Nakamura Kagaku Kabushiki Kaisha); RMA4SOM(available from Nippon Nyukazai Kabushiki Kaisha); Aquaron HS10, AquaronHS20, Aquaron HS1025, Aquaron RN 10, Aquaron RN20, Aquaron RN30, AquaronRN50 and Aquaron RN2025 (available from Dai-ichi Kogyo Seiyaku KabushikiKaisha); NK Ester AMP-60G, NK Ester CB-1, NK Ester SA and NK Ester A-SA;Eleminol JS2 and Eleminol RS30 (available from Sanyo Kasei KogyoKabushiki Kaisha); Latemle WX (available from Kao Corporation); and thelike.

The amount of the surfactant is usually from about 0.05 part by weightto about 5.0 parts by weight on the basis of 100 parts by weight of theethylenically unsaturated monomer.

The initiator is not particularly limited as long as a radical which canbe used for free radical polymerization in an aqueous medium is producedat 20° to 90° C. As the case demands, the initiator can be used incombination with a reducing agent. Examples of the water-solubleinitiator are, for instance, a persulfate, hydrogen peroxide,2,2-azobis(2-amidinopropane) hydrochloride (AIBA) and the like, andexamples of the reducing agent are sodium pyrosulfite, sodiumhydrogensulfite, sodium L-ascorbate, and the like. Examples of theoil-soluble initiator are diisopropylperoxydicarbonate (IPP), benzoylperoxide, dibutyl peroxide, azobisisobutyronitrile (AIBN), and the like.An amount of the initiator is usually from about 0.05 part by weight toabout 2.0 parts by weight on the basis of 100 parts by weight of theethylenically unsaturated monomer.

The polymerization temperature may be from 20° to 90° C.

Examples of the chain transfer agent are a halogenated hydrocarbon (forexample, chloroform, carbon tetrachloride, or the like), mercaptans (forexample, n-lauryl mercaptan, t-lauryl mercaptan or n-octyl mercaptan)and the like. An amount of the chain transfer agent is usually from 0 toabout 5.0 parts by weight on the basis of 100 parts by weight of theethylenically unsaturated monomer.

As the solvent, methyl ethyl ketone, acetone, trichlorotrifluoroethane,methyl isobutyl ketone, cyclohexanone, ethyl acetate, or the like may beused in such a small amount as not to lower workability, safety againstdisaster, safety in environment and safety in production. By adding thesolvent, there is a case where the swelling property of the monomer intothe particles of the fluorine-containing polymer for seed polymerizationis improved.

The seed polymerization can be carried out by known methods, forexample, a method of charging the whole amount of the monomer in one lotin a reaction system in the presence of particles of thefluorine-containing polymer (A), a method of charging a part of themonomer for the reaction and then charging the remaining monomercontinuously or dividedly, or a method of charging the whole amount ofthe monomer continuously.

With respect to the aqueous dispersion of the fluorine-containingpolymer (A) used for the seed polymerization, it is preferable that aparticle size of the polymer in the aqueous dispersion is not more than180 nm, more preferably not more than 150 nm, and the content of thepolymer is in the range of from 30 to 50% by weight, more preferablyfrom 35 to 60% by weight, in order to decrease the particle size afterthe seed polymerization to not more than 200 nm. When the particle sizeafter the seed polymerization exceeds 200 nm, there is a case wheresedimentation stability of the aqueous dispersion is lowered and anincrease in a minimum film forming temperature of the aqueous dispersionoccurs even if resins having the same composition are used.

2. Metal-crosslinking-formable Polyvalent Metal Compound

Examples of the metal-crosslinking-formable polyvalent metal compoundused in the present invention are a metal complex, metal chelate, metalsalt, and the like. Particularly, a compound which is dissociated inwater to produce polyvalent metal ions is preferred. Also, thepolyvalent metal compound can be used in the form of a basic or acidaqueous dispersion. As a metal constituting the metal compound,polyvalent metals such as beryllium, magnesium, calcium, strontium,barium, cadmium, nickel, copper, zinc, zirconium, aluminum, bismuth,antimony, lead, cobalt and iron can be used. In addition, polyvalentmetals such as metals of Group IV of the Periodic Table and alkali earthmetals are preferred.

Examples of the metal complex are complexes of the above-mentionedmetals and amines such as morphorine, monoethanolamine,diethylaminoethanol and ethylenediamine. Examples of the metal chelatesare chelates coordinated in the form of bidentate ligand such asglycinato and alaninato

Examples of the metal salt are inorganic salts, e.g., acetates such aszinc acetate, zirconium acetate, magnesium acetate, cadmium acetate andcopper acetate; nitrates such as zinc nitrate, calcium nitrate, nickelnitrate and zirconyl nitrate; sulfates such as calcium sulfate andmagnesium sulfate; chlorides such as zinc chloride and calcium chloride;carbonates such as zinc carbonate, calcium carbonate, cadmium carbonateand barium carbonate; and the like and organic salts of theabove-mentioned metals, e.g., glycine, benzoic acid and salicylic acid.

Among them, from the viewpoint of water resistance of the obtainedcoating film, compounds of metals such as magnesium, calcium, strontium,zinc and zirconium and in addition, salts and chlorides of those metalswith acetic acid, nitric acid, carbonic acid and sulfuric acid arepreferred. Particularly preferred are zinc acetate, zirconium nitrate,magnesium sulfate and calcium chloride, and the like.

A method of adding the polyvalent metal compound is optionally selectedfrom a method in which the polyvalent metal compound is dissolved inwater and the aqueous solution is added to the aqueous dispersion offluorine-containing seed polymer, a method in which the polyvalent metalcompound is suspended in water and the suspension is added to theaqueous dispersion of fluorine-containing seed polymer, a method inwhich the polyvalent metal compound in the form of powder is directlyadded to the aqueous dispersion of fluorine-containing seed polymer, orthe like.

The carboxyl group and/or acetoacetyl group introduced into thefluorine-containing seed polymer (B) is coordinated on a metal iongenerated from the polyvalent metal compound to form a metal bridgebond. As a result, enhancement of water resistance, anti-blockingproperty and stain-proofing property is exhibited.

From the viewpoint of the coordination of a functional group, that is,carboxyl group and/or acetoacetyl group in the fluorine-containing seedpolymer (B) with a metal ion, it is preferable that an addition amountof the polyvalent metal compound is from about 0.1 equivalent to about 3equivalent on the basis of the functional group. When less than 0.1equivalent, the effect on stain-proofing property and stain removableproperty tends to be small and when in excess of 3 equivalents, waterresistance of a coating film and storage stability of the aqueousdispersion tend to be lowered.

The aqueous-dispersing composition of crosslinkable fluorine-containingresin of the present invention can be used in the form of an aqueouspaint as a surface protective coating for an inorganic substrate such asconcrete, slate and ALC plate and metallic substrate, and further as acoating for coated paper by adding thereto additives such as a pigment,thickener, dispersing agent, anti-foaming agent, anti-freezing agent,film forming aid, ultraviolet ray absorbing agent and antioxidant whichare generally used for aqueous emulsion paints. Also, theaqueous-dispersing composition can be used as a coating for patterningby adding thereto natural stone, synthetic beads for flatting, etc.

Also the aqueous-dispersing composition can be used as an aqueous paintfor painting the exterior and/or interior of a low- or medium-storiedbuilding.

The content of the aqueous-dispersing composition in the paint variesdepending on the form of a paint, coating method, etc. The content maybe selected so that a solid content of the aqueous-dispersingcomposition of the present invention is from about 5% by weight to about95% by weight, usually from 20 to 90% by weight.

For application of such an aqueous paint, a known application method canbe employed. In the application, known coating apparatuses such as abrush, roller, roll coater, air sprayer, airless sprayer, electrostaticcoating machine, dip coater and electrocoating machine can be used.

The above-mentioned aqueous paint can be applied to various substrates,namely, not only to metals such as iron, aluminum, copper and alloysthereof, but also to inorganic materials such as glass, cement andconcrete, resins such as FRP, acrylic resin, vinyl chloride resin,polycarbonate resin and polyurethane resin, wood and fiber. Also ifnecessary, a substrate may be subjected to pre-coating or surfacetreating of an under coating such as an aqueous resin emulsion coatingor a solvent type coating. The coating composition of the presentinvention can be applied after optionally carrying out under-coating orpre-coating. The coating system can be applied as a clear coating orenamel coating on various known substrates having uneven surfacepatterns and color patterns. After the application, the coating film isusually dried for curing at 5° to 300° C. for 30 seconds to one week.The coating thickness is not particularly limited, and is usually fromabout 1 μm to about 200 μm, preferably from 5 to 100 μm, more preferablyfrom 10 to 50 μm.

Since the thus obtained coated article is excellent in stain-proofingproperty, stain removing property, adhesion, weather resistance andchemical resistance and a surface of the coating film has a gloss,lubricity and hardness, the article can be used in a wide range ofapplications. Namely, there are wide applications for coating theinterior and exterior of electric appliances (electronic range, toaster,refrigerator, washing machine, hair dryer, television set, videocassetterecorder, amplifier, radio, electric pot, rice cooker, radio withcassette recorder, cassette deck, compact disk player, video camera,etc.); the interior and exterior of air conditioner such as an indoorunit, outdoor unit, louver, duct, air cleaner and heater); illuminationapparatuses such as a fluorescent lamp, chandelier and a reflectionplate; furniture; machine parts; decorations; combs; frames for glasses;natural fiber; synthetic fiber (in the form of a yarn or woven fabricobtained therefrom); the interior and exterior of office machines(phone, facsimile machine, copying machine (including rollers), camera,overhead projector, prototype projector, clock, slide projector, desk,bookshelf, locker, shelf for documents, chair, bookends and electronicwhiteboard); car-related parts (wheel, door mirror, lace, door handle,number plate, handle and instrument panel); cooking utensils (rangehood, sink, cooking panel, cooking knife, chopping board, water tap, gasrange and ventilator); for indoor coating of a partition plate, bathunit, shutter, blind, curtain rail, accordion curtain, wall, ceiling andfloor; and for outdoor coating of a housing such as a wall, handrail,door and shutter, and for outdoor coating of a building such as sizingmaterial of ceramic, foamed concrete panel, concrete panel, aluminumcurtain wall, steel plate, galvanized steel plate, stainless steelplate, vinyl chloride sheet and window glass; and the like.

EXAMPLES 1. Preparation Example 1

A 1-liter pressure resistive reaction vessel provided with a stirrer wascharged with 500 ml of deionized water, 0.5 g of ammoniumperfluorooctanoate and 0.05 g of polyoxvethylene monostearate (POE40).After repeating introduction of nitrogen under pressure and deaerationand then removing dissolved oxygen, a pressure was applied at 60° C. upto 10 kgf/cm² with a monomer mixture of VdF/TFE/CTFE having a molepercent ratio of 74/14/12. Then, 20 g of a 1% aqueous solution ofammonium persulfate and 1.5 g of ethyl acetate were added and themonomer mixture of VdF/TFE/CTFE having a mole percent ratio of 74/14/12was supplied continuously so that the inside pressure of the vessel wasmaintained constant at 10 kgf/cm². The reaction was continued and 5 g ofa 1% aqueous solution of ammonium persulfate was added every 12 hours.Thus the reaction was carried out for 41 hours. Then the temperature andpressure inside the vessel were returned to normal to give an aqueousdispersion of the particles of fluorine-containing polymer (A) (solidcontent: 42% by weight). With respect to the obtained aqueousdispersion, measurements were carried out as follows.

Average particle size: Measurement was carried out with a laser beamscattering particle size meter (DLS-3000 available from Otsuka Denshi)

The results are such that the average particle size was 134 nm.

2. Preparation Example

A 500-milliliter four neck flask provided with a stirrer, cooling tubeand thermometer was charged with 120 g of the aqueous dispersion of thefluorine-containing polymer obtained in Preparation Example 1, andthereto was added 1.0 g of aqueous solution of alkali salt of alkylallyl sulfosuccinate (brand name ELEMINOL JS2 available from Sanyo KaseiKogyo Kabushiki Kaisha, solid content: 38%) on the basis of the solidcontent. The mixture was heated with stirring in a water bath, and atthe time when the bath temperature reached 80° C., to the mixture wasadded dropwise over one hour an emulsion prepared by emulsifying amonomer mixture comprising 24 g of methyl methacrylate (MMA), 3.0 g ofbutyl acrylate (BA), 0.05 g of acrylic acid (AAc) and 0.02 g ofn-laurylmercaptan (n-LM) with a 0.5% aqueous solution of alkali salt ofalkyl allyl sulfosuccinate. Further, 3.0 g of a 50% aqueous solution ofpolyoxyethylene methacrylate (brand name RMA450M available from NipponNyukazai Kabushiki Kaisha) was added and immediately after that, 1 ml ofa 2% aqueous solution of ammonium persulfate was added to initiate areaction. Three hours after initiation of the reaction, the temperatureinside the bath was elevated to 85° C. and maintained for one hour.Then, after water was removed under reduced pressure for concentration,the mixture was cooled. After adjusting pH to 7 and a solid content to50% with ammonia water, filtration was carried out with a metal net of300 mesh to give a bluish white aqueous dispersion of particles offluorine-containing seed polymer (B). With respect to the aqueousdispersion, a content and an average particle size of a monomer (a)having functional group were measured. The results are shown in Table 1.

Content of a monomer (a) having functional group: % by weight of anadded monomer having a functional group on the basis of the solidcontent of the fluorine-containing seed polymer.

3. Preparation Examples 3 to 9

Aqueous dispersions of particles of fluorine-containing seed polymer (B)were obtained in the same manner as in Preparation Example 2 except thateach component shown in Table 1 was used, and the characteristicsthereof were determined. The results are shown in Table 1.

Abbreviations in Table 1 are as follows.

MMA: Methyl methacrylate

BA: Butyl acrylate

AAc: Acrylic acid

AAEM: Acetoacetoxyethyl methacrylate

n-LM: n-Laurylmercaptan

TABLE 1 Preparation Example 2 3 4 5 6 7 8 9 Addition amount of aqueousdispersion of fluorine- 120 120 120 120 120 93 48 48 containing polymerparticles obtained in Preparation (50.4) (50.4) (50.4) (50.4 (50.4)(39.1) (20.2) (20.2) Example 1 (solid content, part by weight) Radicallypolymerizable monomer (part by weight) MMA 24 23.8 23.5 23 23 25 40 38BA 3 3 3 3 3 9.2 10 10 Aac 0 0.25 0.5 1 — 3.8 7 9 AAEM — — — — 1 — — —n-LM 0.02 0.02 0.02 0.02 0.02 0.04 0.05 0.05 Fluorine-containing seedpolymer (B) Content of monomer (a) having functional 0 0.31 0.65 1.3 1.34.9 9.1 11.6 Group (% by weight) Average particle size (nm) 149 153 156159 161 173 190 192

4. Examples 1 to 11 and Comparative Examples 1 to 4: Preparation ofwhite coating.

A polyvalent metal compound was added and mixed in an amount shown inTable 2 to 100 parts each of the aqueous dispersions obtained inPreparation Examples 2 to 9. Then to the mixture were added 47 parts ofa pigment paste (prepared by mixing and dispersing 70 parts of titaniumoxide (brand name CR97 available from Ishihara Sangyo Kabushiki Kaisha)as a filler, 1 part of ethylene glycol as an anti-freeze agent, 1 partof SOLSPARSE 2000 (available from Zeneca Co., Ltd.) as a dispersingagent, 0.5 part of FS ANTI-FOAM 013B (available from Dow Corning Co.,Ltd.) as an anti-foaming agent and 27.5 parts of water), 0.2 part ofUH420 (available from Asahi Denka Kabushiki Kaisha) as a viscositycontrol agent and 5 parts of diethyl adipate as a film forming aid,followed by mixing sufficiently with a dispersing stirrer to give acoating.

The following items were measured by using the obtained white coating.The results are shown in Table 2. (Initial characteristics of whitecoating film)

Gloss: The obtained white coating was applied on a glass plate using a10 mil applicator, and dried for 20 minutes with a blow dryer at 80° C.A glossiness at 60° reflection was measured using a gloss meter(available from Suga Shikenki Kabushiki Kaisha).

Pencil hardness: Measured according to the pencil hardness test of JISK5400.

Alkali resistance: The obtained white coating was applied on a slate byair spraying to obtain a coating amount of 120 g/m², and then dried for20 minutes with a blow dryer at 80° C. to give a test piece. Withrespect to the coating film, a spot test was carried out with a 5%aqueous solution of sodium hydroxide at 30° C. for one week, andchromaticity coordinates were measured with a colorimeter (CR300available from Minolta Co., Ltd.). A difference Δb in brightness betweenbefore and after the exposure was assumed to be an index for alkaliresistance. The smaller the difference, the more excellent the alkaliresistance.

Hot water resistance: To 200 g each of the aqueous dispersions obtainedin the Examples and Comparative Examples were added 0.5 part of UH420(available from Asahi Denka Kabushiki Kaisha) as a viscosity controlagent and 10 parts of diethyl adipate as a film forming aid, followed bymixing sufficiently with a dispersing stirrer to give a clear coating.The obtained clear coating was applied to a glass plate with a 10 milapplicator and dried for 20 minutes with a blow dryer at 800° C. to givea transparent coating film. The obtained coating film was dipped in hotwater for 20 minutes and removed. Transmittance of visible light at 600nm through the coating film was measured and evaluated as follows.

∘: Transmittance of visible light is not less than 85%

Δ: Transmittance of visible light is not less than 70% and less than85%.

x : Transmittance of visible light is less than 70%. (Stain-proofingproperty of white coating)

The obtained coating was applied to an aluminum plate subjected tochemical conversion treatment using a 10 mil applicator and dried atroom temperature for one week to give a test piece.

Stain-proofing property: Chromaticity coordinates were measured with acolorimeter (CR300 available from Minolta Co., Ltd.) before and after3-month outdoor exposure of the test piece set on an exposure rackplaced at an angle of 30° and facing toward the southern direction inSettsu-shi, Osaka Prefecture. A difference Ab in brightness betweenbefore and after exposure was assumed to be an index forstain-proofness. The smaller the difference, the less the adhesion ofstains.

Stain removable property: An aqueous dispersion of carbon was sprayedonto the surface of the test piece and dried for 2 hours using a blowdryer at 60° C., followed by washing with flowing water using a brush.Chromaticity coordinates were measured with a colorimeter (CR300available from Minolta Co., Ltd.) before and after the test. Adifference Δb in brightness between before and after the test wasassumed to be an index for stain-proofness. The smaller the difference,the more excellent the stain removing property.

Storage stability : The obtained coating was put in a 50 ml glass screwbottle and stored for two weeks in a constant temperature vessel of 50°C. The viscosity of the coating before and after stored was measuredwith a Brookfield type viscometer. The results are classified asfollows.

A: A change in viscosity of the coating is within a range of 80 to 150%of initial viscosity

B: A change in viscosity of the coating is more than 150% and less than200% of initial viscosity

C: A change in viscosity of the coating exceeds 200% of initialviscosity

D: The whole coating is agglomerated

It can be considered that the coatings which can stand under usualservice conditions are those of the above levels A and B.

TABLE 2 Example Com. E 1 2 3 4 5 6 7 8 9 10 11 1 2 3 4 Aqueousdispersion of fluorine- containing seed polymer (B) Preparation ExampleNo. 3 4 5 5 5 5 5 6 7 8 2 2 5 5 9 Addition amount *1 100 100 100 100 100100 100 100 100 100 100 100 100 100 100 (part by Weight) (50) (50) (50)(50) (50) (50) (50) (50) (50) (50) (50) (50) (50) (50) (50) Polyvalentmetal compound *2 (part by weight) Zinc acetate 0.24 0.5 1 — — — 0.2 2.7— 3.73 6.93 0.06 — 3.2 8.84 (1) (1) (1) (0.2) (2.7) (1) (1) (1) (3.2)(8.84) Calcium chloride — — — 0.5 — — — — — — — — — — — (1) Magnesiumnitrate — — — — 0.54 — — — — — — — — — — (1) Zirconium nitrate — — — — —1.2 — — — — — — — — — (1) Copper acetate — — — — — — — — — 0.55 — — — —— (1) Storage stability B B B B B B B B B B B B A C C Physicalproperties of coating film Gloss 73 72 67 65 69 61 72 53 64 63 52 72 7348 43 Pencil hardness B B F H H H F 2H F 2H 2H 2B 2B 2H H Alkaliresistance (Δ b) 1.8 2 2.1 2.3 2.6 2 1.8 3.2 3.1 3.1 4.5 1.7 2 4.3 6.2Hot water resistance ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ X Δ Δ Δ Stain-proofingproperty (Δ L) 8.9 8.6 7.1 5.4 6.3 5.5 7.2 4.8 7.5 4.6 4.9 13.1 15.2 5.67.3 Stain removable property (Δ L) 9.5 7.9 7.6 5.3 6.1 8.9 9.8 5.1 7.34.3 4.1 12.3 14.1 5 6.6 *1 Values in the parentheses are solid contents(part by weight). *2 Values in the parentheses are equivalents to afunctional group.

According to the present invention, it is possible to provide anaqueous-dispersing composition of a crosslinkable fluorine-containingresin which can give a coating having excellent storage stability andforming a coating film having an excellent stain-proofing property andstain removing property, and having sufficient gloss and hardness.

What is claimed is:
 1. An aqueous-dispersing composition ofcrosslinkable fluorine-containing resin which comprises (i) an aqueousdispersion of a fluorine-containing polymer (B) obtained byseed-polymerizing a non-fluorine-containing monomer containing anon-fluorine-containing monomer (a) having carboxyl group and/oracetoacetyl group and a reactive α,β-unsaturated group, in an aqueousmedium in the presence of particles of a fluorine-containing polymer(A), and (ii) a polyvalent metal compound, said carboxyl group and/oracetoacetyl group of said polymer (B) coordinate-bonding to said metalcompound to form a crosslinked structure.
 2. An aqueous-dispersingcomposition of crosslinkable fluorine-containing resin which comprises(i) an aqueous dispersion of a fluorine-containing polymer (B) obtainedby seed-polymerizing a non-fluorine-containing monomer containing anon-fluorine-containing monomer (a) having carboxyl group and/oracetoacetyl group and a reactive α,β-unsaturated group, in an aqueousmedium in the presence of particles of a fluorine-containing polymer(A), (ii) a polyvalent metal compound, and (iii) a pigment, saidcarboxyl group and/or acetoacetyl group of said polymer (B)coordinate-bonding to said metal compound to form a crosslinkedstructure.